Core catcher



March 24, 1931. H K 1,797,550

' coma CATCHER Filed April 1. 1929 Fig.4.

Per 6 Hammer INVENTOR WRNEW I) carried by the rings 3 and 4.

Patented Mar. 24, 1931 UNITED STATES [PATENT OFFICE REX G. 3MB, 01 HOUSTON, TEXAS, ASSIGNOB TO REED ROLLER BIT COMPLNY,

I O1? HOUSTON, TEXAS, A CORPORATION OF TEXAS .coan ca'rcnna Application 1113a April 1,

paratus, and more particularly to core capchers for core drills.

There are two types of core catchers now 5 in common use.that adapted to hold a hard formation core, and that adapted to hold a soft formation core. And if a core drill equipped with a hard formation core catcher passes through soft formation, the soft formation core will not be held, and vice versa. This invention has for one of its objects the provision of a new and improved core catcher adapted to hold both hard and soft formation cores.

Another object is to provide a new and improved core engaging spring finger mounting.

of the core catcher; Fig. 2, a sectional elevation thereof; Fig. 3, a fragmentary sectional includes a plurality of short spring fingers 1 1, and a plurality of long spring fingers 2,

' The inner ring 3 is externally beveled, and

the outer ring 4 is internally beveled to form upwardly and' inwardly inclined meeting faces, indicated at 5, the spring fingersl and 2 being held therebetween. The rings are preferably welded at the It will be obvious to those skilled in the vart thatthe rings-Sand 4, welded together at the bottom, provide a strong and rigid-support for 'thespring fingers without weakening them. The boring of riyet holes and in- -judicious welding has heretofore produced weakened fingers incapable of withstanding the strains to which they are necessarilysubjectedin deep well core drilling operations. When a core drill equipped with my new and improved-core catcher passes through i any formation, both the long and short In the accompanying drawings Fig. 1 is, a top plan view of the preferred embodiment bottQm i mdlcated- 1. A core catcher 1929. Serial No. 351,688

spring fingers will move out of the path of the inwardly'moving core.

When a soft formation has been drilled, and'the drill is elevated, the long fingers 1 will move inwardly to hold the soft formation core 7 within the core barrel 8, as illustrated by Fig. 3. The short fingers may be so disposed that, in that event, they will move inwardly to assist the long fingers.

It is a difficult, if notimpossible, matter to construct a core catcher having relatively long fingers capable of holding a soft forma tion core and also satisfactorily adapted to sustain a hard formation core, the latter of which may comprise solid rock of sufiicient weight to bend and break long fingers. On

the other hand short fingers, while incapable of holding very soft formation cores, possesses great strength and are capable of sustaining heavy hard cores.

Now when the drill is elevated after penetrating a hard formation, the strongand relatively short fingers 1 of my core catcher move inwardly into engagement with the hard core 9, as illustrated by Fig. 4; and firmly support the same in the core barrel 8.

It will be apparent from the foregoing that my new and improved-core catcher comprises few parts characterized by simplicity and strength, and adapted to hold'either a hard or a soft formation core.

My invention is not limited to the specific embodiment shown.

Various changes may be made within the scope of the following claims.

'Iclaim:

having core engaging fingers and a pair ofsupporting rings,'said fingers being held between said rings, and extending upwardly, said rings being welded together atthe bottom.-

2; A core catcher haviiig core engaging long fingers being of a length greater than the radius of said barrel.

4. A core drill having a core barrel, and a. core catcher within said barrel, said catcher having upwardly and inwardly presented, long and short core engaging fingers, said long fingers belng of a length greater than the radius of said barrel, and said short fingers being substantially one-half as long as said long fingers.

5. A core catcher having a ring, long and short fingers carried by said ring and inclined toward the axis of said ring, said long fingers being of a length greater than the radius of said ring.

In testimony whereof, I hereunto aflix my signature.

' REX G. HAMAKER. 

